High-accuracy topography measurement of optically rough surfaces with THz radiation

Author

Hils, B. ; Löffler, T. ; Thomson, M.D. ; von Spiegel, W. ; Weg, C. Am ; May, T. ; Roskos, H.G. ; de Maagt, P. ; Doyle, D. ; Geckeler, R.D.

Author_Institution

THz-Applic. & Syst. Group, Univ. Frankfurt am Main, Frankfurt

fYear

2007

fDate

2-9 Sept. 2007

Firstpage

907

Lastpage

908

Abstract

Characterization of the surface figure of technical materials by interferometry in the visible or near-IR wavelength regime becomes difficult or impossible if the surface is rough on the length scale of a tenth of the wavelength used. In this case, THz radiation can provide an interesting alternative. We demonstrate two methods for the accurate determination of the surface topography: THz heterodyne profilometry and THz ESAD (extended shear angle difference) deflectometry.

Keywords

submillimetre waves; surface topography measurement; THz radiation; extended shear angle difference deflectometry; high-accuracy topography measurement; near-IR wavelength interferometry; optically rough surfaces; surface topography; Length measurement; Mirrors; Optical filters; Optical interferometry; Optical mixing; Optical surface waves; Rough surfaces; Surface roughness; Surface topography; Surface waves;

fLanguage

English

Publisher

ieee

Conference_Titel

Infrared and Millimeter Waves, 2007 and the 2007 15th International Conference on Terahertz Electronics. IRMMW-THz. Joint 32nd International Conference on

Conference_Location

Cardiff

Print_ISBN

978-1-4244-1438-3

Type

conf

DOI

10.1109/ICIMW.2007.4516786

Filename

4516786